Effects of maternal ischemic preconditioning in the colon of newborn rats submitted to hypoxia-reoxygenation insult

Abstract

PURPOSE:To evaluate the effects of maternal remote ischemic preconditioning (IPCr) in the colonic mucosa of newborn rats subjected to hypoxia and reoxygenation. METHODS:Newborn Wistar rats were divided into three groups. Control Group (CG), Hypoxia and Reoxygenation Group (HRG) and Remote Ischemic Preconditioning Group (IPCrG). Hypoxia and reoxygenation was performed 2x per day, with an interval of 6 hours, on the 1st, 2nd and 3rd days of life, with 10 minutes of CO 2 at 100%, followed by 10 minutes O 2 at 100%(HRG/IPCrG). The maternal IPCr was performed 24 hours before delivery by applying a rubber band tourniquet to the left hind limb (IPCrG). Segments of the colon underwent histological (HE) and immunohistochemical analysis for caspase-3 and COX -2. RESULTS:The histological findings showed no intestinal mucosal damage in the CG group and severe lesions in HRG that was attenuated in the IPCrG (p<0.05). The expression of the apoptotic cells was lower in the HRG group than in the CG and IPCrG. The COX-2 expression was intense in HRG and attenuated in the IPCrG (p<0.05). CONCLUSIONS:Maternal IPCr protected the colonic mucosa of newborn rats subjected to hypoxia and reoxygenation, reducing the morphological alterations and inflammatory response. It ameliorates the occurrence of apoptosis, keeping the physiological process of renewal and regeneration in the epithelial lining of the colonic mucosa.Key words: Enterocolitis, Necrotizing. Colon. Apoptosis. Rats. Effects of maternal ischemic preconditioning in the colon of newborn rats submitted to hypoxia-reoxygenation insultActa

Neonatal necrotizing enterocolitis rat model attenuated by a remote ischemic preconditioning in the pregnant

“…the Hypoxia/Reoxygenation group (Median of positive cells C=14 (10-15); H/R=8 (0-12); rIPC=12 (11)(12)(13)(14); r-IPCvsH/R, p=0.0002), which, in addition, showed decreased crypt depth and villus height. The remote ischemic preconditioning preserved the proliferative activity, as well the depth of the crypts (C=29 µm; H/R=16 µm; rIPC=24 µm, r-IPCvsH/R, p=0.01) and villus height (C=87 µm, H/R=45 µm; r-IPC=84 µm, r-IPCvsH/R, p=0.01) ( Figure 2).…”

“…In our lab, it was shown that r-IPC applied on pregnant rat minimized the occurrence of colonic NEC in their pups 13 . Considering the systemic effect of r-IPC against IR lesions and that ischemia is a relevant factor in the occurrence of NEC; further, the ileum is also compromised in this disease; it was decided to test the hypothesis that r-IPC applied in pregnant rat might attenuate the small bowel lesions in an experimental NEC model.…”

Comparative evaluation of the osteogenic capacity of human mesenchymal stem cells from bone marrow and umbilical cord tissue

“…The H-score was calculated by combining the percentage of immunoreactive cells (%) with an estimate of the staining intensity (0, 1, 2 or 3), as described previously (24). An H-score of 9-12 was considered to represent strong immunoreactivity ('+++'), 5-8 was considered moderate ('++'), 1-4 was considered weak ('+') and 0 was scored as negative ('-') (25,26).…”

Remote ischemic preconditioning and tacrolimus in the fetal small bowel transplant in mice

“…In the small intestine dysfunction observed after sustained warm ischemia was prevented if preconditioning was carried out before the ischemia 4 . The mechanism of remote preconditioning is not limited to one organ system either: Freitas et al 5 noted that maternal IPC protected the colonic mucosa of neonatal rats subjected to hypoxia and reoxygenation, reducing the morphological changes and the inflammatory response. In another study 6 , the authors showed that the IPC protected against ischemia-reperfusion injury in remote lung intestinal ischemiareperfusion on or hepatic model with acute diabetes.…”